The main part and the knob should be printed using PLA. The TPU string insert has two options a thicker and thinner one to choose which is more comfortable. It gets in the way slightly but its a way to capo without having to drill holes in your banjo. I used a piece of TPU from a failed print to cover the bolt so it doesn't mark the neck. I simply used super glue to glue it on. The nut is a M5-.8 hex nut and the bolt is M5-.8 x 12 hex head. I also super glued the knob to the bolt. It fits on my cheap Epiphone banjo, hopefully it fits many other brands and models.